Henry kroeger



(Model) H. KROEGER.

PIANO FORTE FRAME.

Patented May 27. 1884,

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INVENTQB ATTORNEYS.

UNiTE STATES PATENT @rrrcn.

HENRY KROEGER, OF NEWV YORK, N. Y.

PIANO-FORTE FRAME.

SPECIFICATION forming part of Letters Patent No. 299,?79, dated May 27, 1884.

Application filed November 16, 1883. (Modem To aZZ whom it may concern.-

Be it known that I, HENRY KROEGER, of the city, county, and State of New York, have invented a new and useful Improvement in Piano-Forte Frames, of which the following is a full, clear, and exact description.

The object of my invention is to provide a new and improved metal frame for piano fortes, which frame is so constructed that all the edges of the sounding-board can be held in contact with and secured to the same, whereby full, strong, and rich tones can be produced on the instrument.

The invention consists in a pianoframe hav ing on its back bearing-surfaces for thesounding-board along all the edges of the same, which frame is provided in one corner with a triangular part having its inner surface flush with the bearing-surfaces for the sounding board.

Reference is to be had to the accompanying drawings, forming a part of this specification, in which similar letters of reference indicate corresponding parts in all the figures.

Figure '1 is a front view of my improved piano-forte frame, the sounding-board being secured to the back of the same. Fig. 2 is a cross-sectional elevation of the same on the line as m, Fig. 1. Fig. 3 is a rear view of the same with the frame H omitted and parts of the sounding-board broken out. Fig. 4 is an end view, also without the frame H. Fig. 5 is a detail sectional View on the line :1; y, Fig 1.

The piano-forte plate A, provided with ribs, braces, and openings in the usual manner, is provided at its top and bottom edges with flanges B, projecting toward the rear and with flanges G at the end edges, the top and bottom flanges, B, projecting farther from the rear surface of the plate A than the end flanges, O. The top and bottom flanges are rabbeted or cut out in their inner surfaces to form shoulders or offsets D, which are in the sameplane with the inner edges of the end flanges, 0. At the lower right-hand, corner the frame is provided with a diagonal offset, E, beveled from the front toward the rear of the frame, whereby the triangular corner F of the frame will be brought out of the plane of the front of the frame. The said triangular part F will be in a plane parallel with the plane of the front of the frame, and the rear surface of the part F will be in the same plane with the shoulders D and the rear edges of the end flanges, C. The sounding-board G has a frame, H, of the usual construction, secured on one surface along the edges, and the opposite surface is placed and bears along its edges on the shoulders D and on the inner edges of the flanges C, the flanges B overlapping the top and bottom edges of the sounding-board, as shown. The front surface of the sounding-board rests against the inner surface of the part F of the frame, as the inner surface of the part F is in the same plane with the inner edges of the flanges C and with the shoulders D. The sounding board is held to the frame A by bolts or screws passed through the board and through the flanges and part F of the frame. The sounding-board is thus held firmly on the frame along all the edges of the soundingboard, and has a firm and solid bearing on the frame. The vibrations of the board will thus be very powerful and regular, as the sounding-board has no loose edges. As the lower right-hand corner of the sounding-board is held securely on the rear surface of the part F of the frame, the said corner of the board cannot vibrate. The other parts of the board are held sufficiently from the frame to permit of strong vibrations without mutilating the tones or interfering with them. It is necessary to prevent the lower right-hand corner of the sounding-board from vibrating, as otherwise the-vibrating part of the board would be too large. In some pianos made heretofore the said corner'has been cut off for the purpose of reducing the vibrating part of the board; but I prefer to bind the said part to the soundi1ig board, as thereby the soundingboard and the frame will be more firmly united. I am aware that soundingboards have been secured to thin supporting-frames along all their edges; and I am also aware that frames have been provided with a depressed corner projecting below the sounding-board, and I therefore do not claim such inventions.

Having thus described my invention, I claim as new and desire to secure by Letters Patent 1. The combination, witha sounding-board, of a frame provided on its rear side with bearing-surfaces for the sounding-board along all the edges 01' the same, and with a corner l'orlnders 1), formed in the inner surfaces, with end ing a bearing for a corner of the sounding flanges, (J, the edges of which are 011 the same beard, substantially as herein shown and deplane with the shoulders 1), and with a trian- T 5 scribed. gnlar part, F, forming an. Offset, 1 3, in the 5 2. A pianowl'rame provided with rabbcted frame, and havingits inner surface on thcsame flanges l3 and end flanges, C, the edges of plane with the shoulders l) and theinneredges which are in the same plane with the surfaces 01' the flanges (J, snhstantiallyas herein shown of the shoulders or eflsets formed by the raband described. bets in the flanges B, substantially as herein HENRY KROEGER.

10 shown and described. \Vitnesses:

A piano-forte frame constructed with top G. ILM'UNIIEIAI,

and bottom flanges, 13, having oll'sets ershoul- Oscar]: F. (New. 

